SORGUES, france —A T-shirt worn by a 3-year-old nursery-schooler named Jihad has led to an unusual and politically charged criminal trial here that tests the limits of free speech — and common sense — in a France increasingly ill at ease with its growing Muslim population.

“I am a bomb,” the shirt said on the front. The back read, “Jihad Born Sept. 11.”

The prosecution and the defense both have predicted that the outcome is likely to become a legal precedent as the government and justice system handle recurring friction between France’s 8 percent Muslim minority and the majority of the country’s 65 million inhabitants who recognize their roots in an ancient Christian tradition.

The tensions have been increasingly visible as French soldiers combat Islamist guerrillas in Mali, in northwestern Africa, and anti-terrorism police scour the country’s poor suburbs in search of Muslim youths drawn by the call to jihad or revenge.

The case in Sorgues, a town just north of Avignon, began Sept. 25 at an unlikely place: the Ramieres de Sorgues municipal nursery. As she dressed the children after a lunch break, a teacher there became alarmed when she saw Jihad’s T-shirt.

Although little Jihad was, in fact, born on Sept. 11, the teacher saw an outrageous reference to Islamic war and the al-Qaeda terrorist attacks on the United States on Sept. 11, 2001. Concerned, she spoke with the principal, who was equally upset and called in Jihad’s 35-year-old Moroccan-born mother, Bouchra Bagour.

Told of the indignation produced by Jihad’s shirt, the single mother, who works as a secretary, apologized and said she had no intention of conveying a political message via her toddler. The shirt, she pledged, would be put away for good.

But the issue did not rest there. The principal wrote a report to school district authorities. A copy of the report landed on the desk of Mayor Thierry Lagneau. The mayor, from the conservative Union for a Popular Movement party, said in an interview that he regarded the T-shirt as a “provocation,” and he stepped into action.

Lagneau wrote a letter to the region’s chief prosecutor, Bernard Marchal, asking for an investigation for possible criminal prosecution as well as a “thorough” investigation by child-welfare authorities to see whether Bagour was a fit mother.

Before long, Bagour and her brother, Zeyad Bagour, 29, were called in separately by national police and questioned about their religious and political leanings.

After the police investigation, no terrorism-related charges were brought. But the prosecutor decided to charge Bagour and her brother with “apology for crime,” which under a 1981 French law carries a penalty of up to five years in prison and a $58,000 fine.

Zeyad Bagour said he bought the shirt without thinking of any political message.

The front already had the words “I am a bomb” printed on it, but he understood that as an expression equivalent to “I am a real looker.”

“I did it on a lark,” he said, apologizing for any alarm he may have raised. “It wasn’t even meant as a joke.”

The owners of Boulder’s Sterling University Peaks apartments, who this summer were cited for illegally subdividing 92 bedrooms in the complex, have reached an agreement to settle the case for $410,000, the city announced Thursday.